Steps, stairs and the like, and a method of constructing same

ABSTRACT

A flight of steps, stairs and the like heated by means of a heating medium passing through a pipe located within the steps, stairs etc. The pipe is located totally within the confines of the step structure and extends in a tortuous path generally longitudinally of the flight of steps. The pipe is permanently pre-shaped so as to present interconnected, generally arcuate looped portions and can be made to conform to the step configuration substantially solely by twisting the pipe at selected regions along its length.

May 6, 1975 United States Patent 1 Svenstam STEPS, STAIRS AND THE LIKE, AND A Primary Examiner-Charles Sukalo METHOD OF CONSTRUCTING SAME [75] Inventor: Sven Gunnar Svenstam,

Upplands, Vasby, Sweden ABSTRACT [73] Assignee: Gr'a'nges Essem Aktiebolag Filed:

[22] 28, 1972 A flight of steps, stairs and the like heated by means of a heating medium passing through a pipe located PP NO.I 284,456 within the steps, stairs etc. The pipe is located totally within the confines of the step structure and extends in a tortuous path generally longitudinall of steps. The pipe is permanently pre [30] Foreign Application Priority Data b Ofdthe flight -s ape so as to Aug. 27, 1971 Sweden..................,.......... 10908/71 present interconnected generally arcuate looped p tions and can be made to conform to the step configuration substantially solely by twisting the pipe at selected regions along its length.

[52] US. 29/1573 R; 165/47 [51] Int. F24h 3/00 165/1, 47; 237/1 R;

[58] Field of Search...................

[56] References Cited UNlTED STATES PATENTS 3,157,358 11/1964 Birkemeier....................... 237/] R 8 Claims, 6 Drawing Figures PATENTEU vs 3.881.235

' SHEET 20F 2 STEPS, STAIRS AND THE LIKE, AND A METHOD OF CONSTRUCTING SAME The present invention relates to steps. stairs and the like of the type with which at least one pipe, suitably made of a plastics material, is mounted beneath the tread of the steps or stairs and arranged to conduct a heat transmitting medium to maintain the steps or stairs free from ice and snow. The invention also relates to a method of constructing such steps or stairs.

When constructing steps or stairs of the aforementioned type, the pipe through which the heating medium is conducted is normally delivered to the working site in the form of pipe which has been wound in a straight and cold condition onto drums or the like of relatively large diameter, and hence from the point of view of laying the pipe, is equivalent to straight pipe. Because of the relative inflexibility of the pipe, it is normally necessary to place it on the structural members of the steps, e.g., the step reinforcing frame structure, in such a manner that portions of the pipe in the finished steps extend transversely of the steps beneath the treads, while other portions of the pipe connecting together the transversely extending pipe portions are located outside the steps in the form of wide connecting loops. The connecting loops must be placed externally of the steps on either side thereof and fulfil no useful purpose other than that of connecting together the transversely extending pipe portions. This method of construction often results in high buildings costs and excessively bulky step or stair structures.

With another method of constructing steps or stairs of the aforementioned type, the system of pipes for conducting the heating medium is constructed of straight lengths of pipe placed transversely and longitudinally of the steps and connected together by means of pipe couplings or the like. Although this method of construction enables the steps or stairs to be kept within reasonable dimensions, the costs involved are high and the flow conditions for the heating medium unfavourable, while at the same time there is a serious danger of leaks occurring.

For the purpose of eliminating these disadvantages, it is proposed in accordance with the invention that in the construction of steps or stairs of the aforementioned type each pipe is preformed to a permanent shape so as to present interconnected generally arcuate portions and extends substantially in the long direction of the steps or stairs in a tortuous path such as to present substantially arcuate interconnected looped portions located within the confines of the steps, stairs and the like and curving alternately towards either side of the steps, the pipe being arranged in planes which extend generally parallel with the step treads and risers under which it passes and at the points where it passes between tread and riser extends generally perpendicular to the long direction of said steps.

The method of the invention for producing a flight of steps, stairs and the like, having at least one pipe for carrying heating medium arranged beneath the treads of the steps to maintain thev steps free from ice and snow, and with which each pipe is mounted to the frame structure of the steps, such as a step reinforcing structure, at least prior to forming the external tread surface of the steps is characterized by the steps of using at least one pipe permanently pre-shaped to present interconnecting generally arcuate portions, arranging the pipe so as to conform to the step frame structure substantially solely by twisting the pipe about its long axis in regions along the length thereof, and mounting said pipe to said step frame structure in a manner such that the pipe extends substantially in the longitudinal direction of the finished steps in such a tortuous path that it presents interconnected, generally arcuate looped portions curving alternately towards either side of the steps, the pipe being placed in planes which extend generally parallel with the treads and risers under which it passes and caused to extend generally perpendicular to the long directions of said flight of steps at the point where said pipe passes between tread and riser.

The invention will now be described in more detail with reference to an embodiment thereof illustrated in the accompanying drawing, further advantages and features of the invention being made apparent in connection therewith. In the drawing,

FIG. 1 is a perspective view of a flight of steps constructed in accordance with the invention,

FIG. 2 illustrates in larger scale a portion of the steps shown in FIG. 1,

FIG. 3 is a sectional view taken through the line 11]- lll in FIG. 2, and

FIGS. 4-6 illustrate in perspective three forms to which the pipes laid in the steps can be permanently pre-shaped before being embodied in the steps.

In the drawing like elements have been identified by like reference numerals, and the reference numeral 10 indicates generally a flight of steps or stairs extending between an upper platform level 11 and a lower platform level 12. The visible side of the steps is shown at 13. Embodied in the steps 10, the treads and risers of which are shown at 14 and 15 respectively, are plastic pipes 16 through which is arranged to pass a heating medium for the purpose of maintaining the steps free from ice and snow. The heating medium is suitably in the form of hot water, which may previously have been used for heating houses, apartment buildings or the like.

One end of each pipe 16 is connected to an inlet 17 and the other end to an outlet 18 for heating medium. The pipes 16 extend generally in the longidudinal direction of the flight of steps 10 in such a tortuous path as to present within the confines of the steps substantially U-shaped interconnected looped portions 19, 20 which extend alternately towards either side of the steps. Each of the looped portions 19, 20 is located in a plane which lies generally parallel with the surface of its respective riser or tread, the looped portions located beneath the tread surfaces 14 being identified by the reference numeral 19 and the looped portions located inwardly of the riser surface 15 with the reference numeral 20. The pipes 16 extend substantially perpendicular to the longitudinal direction of the flight of steps 10 at the junctions 21 between the treads and risers. The pipes 16 are pre-shaped in a manner such that they present interconnected, substantially arcuate portions of such shape and size as to render it unnecessary to bend or straighten the arcuate portions, or at least to more than a slight extent, in order to form the looped portions 19, 20 when mounting the pipes 16 on the building framework (not shown) of the steps. This framework may comprise, for example, a reinforcing frame structure for the steps or a stair-like body, on which the pipes are mounted and then embedded in the material forming the outer layer of the tread and riser. The permanent shape of the pipes 16 can readily be imparted thereto in manufacture, by shaping the pipes while hot and cooling them in the shaped condition. Shaping of the pipes can be effected at the pipe-making factory, in connection with the pipe extrusion process applied to produce the pipes. Alternatively, it is often more suitable to shape ready manufactured pipes, for example by passing hot water through the pipes so that the pipes can be bent to the desired shape, and then permanently fixing the shape by passing a cooling medium such as cold water through the pipes.

According to the invention, pipes can be used which have been permanently pre-shaped to follow a substantially sinus-haped path or a path of similar tortuous configuration so that the pipes need generally only to be twisted through about 90 around their axis in certain regions along the length thereof in order to be made to conform in the desired manner to the step structure. Pipes in this form are less suitable, however, from the point of view of general handling and transportation of the pipes. A more advantageous pipe form is described hereinafter with reference to FIGS. 46.

As will be seen from FIG. I, the pipes 16 extend parallel to one another, wherewith each tread and riser of the steps will be heated substantially uniformly across the whole of its surface by the heating medium flowing through the pipes. Each pipe 16 passes backwards and forwards once between the top 11 and the foot 12 of the steps 10, although it will be readily perceived that each pipe 16 can form more than two pipe sections extending between the stair-foot and the stair-head. In this connection, it is suitable that the inlet 17 and the outlet 18 are located in the illustrated manner at the same end of the flight of steps, whereby the heat from the heating medium flowing through the pipes is distributed generally uniformly over the whole flight of steps 10. The inlet 17 and outlet 18 arranged at the top platform surface 11 of the steps are joined to the pipes 16 by welding joints or pipe couplings (not shown), the pipe sections of each pipe 16 extending backwards and forwards between the foot and the head of the steps are located parallel with each other and are joined together at the lower end of the steps by means of a looped portion 22 formed by a portion of the pipe 16 and arranged beneath the bottom platform surface 12 of the steps.

In FIG. 4 there is illustrated a helically wound, permanently shaped pipe 23, which is a suitable form from the aspect of transportation and handling of the pipe and which can be used to advantage with a flight of steps or stairs constructed in accordance with FIGS. 1-3. It will readily be understood that looped portions similar to those at 19 and 20 can readily be obtained by twisting the pipe 23 through roughly 90 about its long axis at regions along the helically coiled pipe spaced about 180 apart. This is also evident from FIG. 2, from which it can be seen that a turn of a helix would be obtained by turning the uppermost loop portion 20 through 90 to the upper tread, as shown by the chain line 24, and that another turn of a helix would be obtained if the lowermost loop portion 19 were also turned through 90 to the lower tread, as shown by the chain line 25. If the depth of the tread exceeds the height of the riser to compensate for the difference the arcuate pipe portions forming the looped portions in the tread can be straightened out slightly, and/or the arcuate pipe portions forming the looped portions in the risers may be more tightly bent, and/or a larger portion of each turn of the helically wound pipe may be used to form the looped portions in the treads and a smaller portion of each turn may be used to form the looped portions in the riser. When mounting the pipe 23 on the step frame structure, it is also possible to straighten or to bend the pipe somewhat, in a manner to obtain in the finished flight of steps generally semicircular arcuate looped portions 19, 20 respectively of greater and smaller radius than the radius of the coils of the helically wound pipe 23. Suitably, however, the dimensions of the turns of the helically wound pipe 23 are selected so that the length of a turn is substantially equal to the total length of the looped portions 19, 20 in a tread l4 and adjacent riser 15 of the finished steps.

The permanently shaped pipe 26 illustrated in FIG. 5 differs from pipe 23 inasmuch as the turns of pipe 26 are oval and not circular. When using the pipe 26, generally arcuate looped portions which correspond to the looped portions 19, 20 but which extend to a greater or lesser extent in the transverse direction of the steps can be obtained by twisting the pipe through 90 around its long axis, at selected regions spaced approximately l apart.

FIG. 6 illustrates a pipe 27 which has been permanently shaped to the form of sequentially arranged loops of roughly figure-eight configuration and which can be used with the method of the present invention. When mounting the pipe to the frame structure of the steps, the pipe can be turned through about its long axis at regions 28 to obtain in each tread and riser two looped portions, each of which extends towards its respective side of the steps. Alternatively, the pipe 27 can be twisted at regions 29, wherewith the portions of the pipe forming three-quarters of the eight-shaped loops are placed beneath the treads l4 and the slightly S- shaped portions of the pipe therebetween are placed behind the risers 15.

The invention is not restricted to the described and illustrated embodiment, but can be modified within the scope of the following claims.

I claim:

1. A method of making a flight of steps, stairs and the like having at least one pipe for carrying heating medium arranged beneath the treads of the steps to maintain the steps free from ice and snow, each pipe being mounted to the frame structure of the steps at least prior to forming the external tread surfaces of the steps, the method comprising the steps of twisting at least one permanently pre-shaped pipe having interconnecting and substantially arcuate portions about the longitudinal axis of said pipe at regions along the length thereof to conform said pipe to the configuration of the step frame structure, and mounting the twisted pipe to said step frame structure with the pipe extending substantially in longitudinal direction of the finished steps in planes located generally parallel with the treads and risers of said steps, said interconnected and substantially arcuate portions curving alternatively toward either side of the steps, said pipe extending substantially at right angles to the longitudinal direction of said flight of steps at the point where the pipe passes between respective treads and risers.

2. A method according to claim 1, for making a flight of steps, stairs and the like wherein a number of pipes extend in a tortuous path in longitudinal direction of, the steps, and including the step of mounting the pipes to the step frame structure so that said pipes extend generally parallel to each other along the finished steps.

3. A method according to claim 2, including the step of mounting each pipe to the step frame structure to form pipe portions extending between the top and bottom of the finished steps in longitudinal direction thereof.

4. A method according to claim 3, including the step of extending the pipe portions in a tortuous path between the top and bottom of the steps so that said pipe portions extend parallel to one another.

5. A method according to claim 4, including the step of mounting each pipe to the step frame structure to form a single. substantially U-shaped looped portion extending between two adjacent treads and two adjacent risers respectively of the finished steps.

6. A method according to claim 1, wherein said preshaped pipe comprises substantially helically wound pipe.

7. A method according to claim 6, including the step of dimensioning the turns of the helically wound pipe so that the length of one turn is substantially equal to the combined length of the looped pipe portions in a tread and an adjacent riser of the finished steps.

8. A method according to claim 1, wherein said pipe is permanently shaped to form a number of sequentially arranged and substantially eight-shaped loop portions. =l 

1. A method of making a flight of steps, stairs and the like having at least one pipe for carrying heating medium arranged beneath the treads of the steps to maintain the steps free from ice and snow, each pipe being mounted to the frame structure of the steps at least prior to forming the external tread surfaces of the steps, the method comprising the steps of twisting at least one permanently pre-shaped pipe having interconnecting and substantially arcuate portions about the longitudinal axis of said pipe at regions along the length thereof to conform said pipe to the configuration of the step frame structure, and mounting the twisted pipe to said step frame structure with the pipe extending substantially in longitudinal direction of the finished steps in planes located generally parallel with the treads and risers of said steps, said interconnected and substantially arcuate portions curving alternatively toward either side of the steps, said pipe extending substantially at right angles to the longitudinal direction of said flight of steps at the point where the pipe passes between respective treads and risers.
 2. A method according to claim 1, for making a flight of steps, stairs and the like wherein a number of pipes extend in a tortuous path in longitudinal direction of the steps, and including the step of mounting the pipes to the step frame structure so that said pipes extend generally parallel to each other along the finished steps.
 3. A method according to claim 2, including the step of mounting each pipe to the step frame structure to form pipe portions extending between the top and bottom of the finished steps in longitudinal direction thereof.
 4. A method according to claim 3, including the step of extending the pipe portions in a tortuous path between the top and bottom of the steps so that said pipe portions extend parallel to one another.
 5. A method according to claim 4, including the step of mounting each pipe to the step frame structure to form a single, substantially U-shaped looped portion extending between two adjacent treads and two adjacent risers respectively of the finished steps.
 6. A method according to claim 1, wherein said pre-shaped pipe comprises substantially helically wound pipe.
 7. A method according to claim 6, including the step of dimensioning the turns of the heLically wound pipe so that the length of one turn is substantially equal to the combined length of the looped pipe portions in a tread and an adjacent riser of the finished steps.
 8. A method according to claim 1, wherein said pipe is permanently shaped to form a number of sequentially arranged and substantially eight-shaped loop portions. 